Bottom Line:
Replacement of the commonly used fetal calf serum (FCS) with human platelet lysate and plasma (PLP) to support cell growth may reduce some of these risks.In two-dimesional PLP cultures, cellular proliferation appeared to decrease during later stages of differentiation, while in the FCS group the number of cells increased throughout the experiment.As PLP is free of animal components, and thus represents reduced risk for xenogeneic infection, its use for human MSC-induced bone repair in the clinic by the three-dimensional live implants presented here appears a promising therapy option.

Introduction: Bone marrow-derived mesenchymal stromal cells (MSCs) have been intensely studied for the purpose of developing solutions for clinical tissue engineering. Autologous MSCs can potentially be used to replace tissue defects, but the procedure also carries risks such as immunization and xenogeneic infection. Replacement of the commonly used fetal calf serum (FCS) with human platelet lysate and plasma (PLP) to support cell growth may reduce some of these risks. Altered media could, however, influence stem cell differentiation and we address this experimentally.

Methods: We examined human MSC differentiation into the osteoblast lineage using in vitro two- and three-dimensional cultures with PLP or FCS as cell culture medium supplements. Differentiation was followed by quantitative polymerase chain reaction, and alkaline phosphatase activity, matrix formation and matrix calcium content were quantified.

Results: Three-dimensional culture, where human MSCs were grown on collagen sponges, markedly stimulated osteoblast differentiation; a fourfold increase in calcium deposition could be observed in both PLP and FCS groups. PLP-grown cells showed robust osteogenic differentiation both in two- and three-dimensional MSC cultures. The calcium content of the matrix in the two-dimensional PLP group at day 14 was 2.2-fold higher in comparison to the FCS group (p

Conclusions: Human PLP was at least equal to FCS in supporting osteogenic differentiation of human MSCs in two- and three-dimensional conditions; however, proliferation was inferior. As PLP is free of animal components, and thus represents reduced risk for xenogeneic infection, its use for human MSC-induced bone repair in the clinic by the three-dimensional live implants presented here appears a promising therapy option.

Fig1: Cell proliferation and alkaline phosphatase (ALP) activity in two-dimensional (2D) cell culture. Cells were plated at the density of 5 × 103/cm2, changed into osteogenic medium and cultured up to 28 days in 2D culture. a Cell enumeration was performed on days 1, 7, 14, 21 and 28. b ALP activity was measured spectrophotometrically in each cell culture well at days 4, 7, 14 and 21. CTRL control, DIFF differentiation, FCS fetal calf serum, ns not significant, PLP platelet lysate and plasma

Mentions:
To determine the rate of increase in cell number, cells were harvested and counted during the 28-day differentiation period (Fig. 1a). After plating, the number of PLP-grown MSCs increased 3.5-fold by day 7 of culture, and remained constant thereafter. The cells grown in FCS continued to proliferate throughout the experiment, resulting in significantly more cells on day 28 (FCS differentiated, 140,460 ± 17,793 cells/well; PLP differentiated, 39,000 ± 4258 cells/well; p < 0.01). The growth in MSC number of the control cultures paralleled that of the differentiating cultures.Fig. 1

Fig1: Cell proliferation and alkaline phosphatase (ALP) activity in two-dimensional (2D) cell culture. Cells were plated at the density of 5 × 103/cm2, changed into osteogenic medium and cultured up to 28 days in 2D culture. a Cell enumeration was performed on days 1, 7, 14, 21 and 28. b ALP activity was measured spectrophotometrically in each cell culture well at days 4, 7, 14 and 21. CTRL control, DIFF differentiation, FCS fetal calf serum, ns not significant, PLP platelet lysate and plasma

Mentions:
To determine the rate of increase in cell number, cells were harvested and counted during the 28-day differentiation period (Fig. 1a). After plating, the number of PLP-grown MSCs increased 3.5-fold by day 7 of culture, and remained constant thereafter. The cells grown in FCS continued to proliferate throughout the experiment, resulting in significantly more cells on day 28 (FCS differentiated, 140,460 ± 17,793 cells/well; PLP differentiated, 39,000 ± 4258 cells/well; p < 0.01). The growth in MSC number of the control cultures paralleled that of the differentiating cultures.Fig. 1

Bottom Line:
Replacement of the commonly used fetal calf serum (FCS) with human platelet lysate and plasma (PLP) to support cell growth may reduce some of these risks.In two-dimesional PLP cultures, cellular proliferation appeared to decrease during later stages of differentiation, while in the FCS group the number of cells increased throughout the experiment.As PLP is free of animal components, and thus represents reduced risk for xenogeneic infection, its use for human MSC-induced bone repair in the clinic by the three-dimensional live implants presented here appears a promising therapy option.

Introduction: Bone marrow-derived mesenchymal stromal cells (MSCs) have been intensely studied for the purpose of developing solutions for clinical tissue engineering. Autologous MSCs can potentially be used to replace tissue defects, but the procedure also carries risks such as immunization and xenogeneic infection. Replacement of the commonly used fetal calf serum (FCS) with human platelet lysate and plasma (PLP) to support cell growth may reduce some of these risks. Altered media could, however, influence stem cell differentiation and we address this experimentally.

Methods: We examined human MSC differentiation into the osteoblast lineage using in vitro two- and three-dimensional cultures with PLP or FCS as cell culture medium supplements. Differentiation was followed by quantitative polymerase chain reaction, and alkaline phosphatase activity, matrix formation and matrix calcium content were quantified.

Results: Three-dimensional culture, where human MSCs were grown on collagen sponges, markedly stimulated osteoblast differentiation; a fourfold increase in calcium deposition could be observed in both PLP and FCS groups. PLP-grown cells showed robust osteogenic differentiation both in two- and three-dimensional MSC cultures. The calcium content of the matrix in the two-dimensional PLP group at day 14 was 2.2-fold higher in comparison to the FCS group (p

Conclusions: Human PLP was at least equal to FCS in supporting osteogenic differentiation of human MSCs in two- and three-dimensional conditions; however, proliferation was inferior. As PLP is free of animal components, and thus represents reduced risk for xenogeneic infection, its use for human MSC-induced bone repair in the clinic by the three-dimensional live implants presented here appears a promising therapy option.